1. Field of the Invention
This invention relates generally to sample collection for chemical analysis. It relates particularly to a sample collection system which provides a representative sample and which avoids contamination of the sample during collection, preparation and storage for subsequent analysis.
2. Description of the Related Art
The universally accepted maxim that a chain is no stronger than its weakest link has particular application to the procedures of chemical analysis. That is to say, all of the intricate work in conducting a qualitative and quantitative analysis will be of little value if the sample presented for this analysis is not representative of the mass from which it was obtained, and/or if such a sample was contaminated during collection, preparation, and storage.
With particular regard to the analysis of liquids, especially aqueous media such as lakes, ponds, reservoirs, rivers, and effluent streams, the analytical results obtained are often crucial. Indeed, the quality of analytical data obtained for regulatory purposes, such as derivation of site specific water quality standards, establishing wastewater permit discharge limitations, reasonable potential determinations, and in determining the compliance status of dischargers, must meet very high standards because of the legal significance of this data. In recent studies, it has been clearly demonstrated that the quality of trace metal data may be compromised because of contamination of samples during collection, preparation, and storage. Therefore, the use of clean techniques for sampling as well as analysis is critical to obtaining representative and accurate data.
Although numerous improved sampling techniques and systems have been developed over the years, today's exacting technical and legal standards required even better sampling systems for the provision of truly representative samples wherein significant contamination is eliminated.